Take responsibility for your own mistakes. In other words, I can understand your irritation and frustration, but don't expect changes to be made to the game.
Fine, I'll spell it out for you. Don't queue pug when you can queue with a friend. If you care about your leaderboard status (which btw has nothing to do with 'competitive play' due to existence of pug vs premade) then you will never queue with a random stranger.
What you're getting now IS 'competitive mode', it's just you and some randoms versus some other randoms. People quitting is part of the scenario and really should figure in your strategy, else you're failing at it.
So your OP boils down to 'I pug and hate it when unreliable pugs quit' - hence, fuck off.
The leaderboard is a red herring in your thought process. It does not identify losses and victories where people dropped out, it only cares about win or loss. When you pug, you sabotage your leaderboard rank progression. In order to avoid this sabotage, queue with a solid team-mate and never pug.
BTW to pre-empt your reply: Relic won't add a blacklist because people would abuse it by narrowing down the list to unreasonable levels. Queues would take forever and people would get ganked via blacklist manipulation. It'll never happen.
Im gonna close down the salt mine I just financed in Chille.
Why bother financing something when you can provide me with all the free salt in the world
All I gotta do is just browse these forums.
Back on topic, Vamp you are just being bated bro. Dont fall for it.
Also, hit me up if you ever want to go to comp 4v4.